1. Field of the Invention
The present invention relates to fluid control systems and more specifically to a novel flapper nozzle actuator system having a rotatable turbine like flapper.
2. Description of the Prior Art
Nozzle flapper valves are well known in the art and are often used as pilot valves in industrial control instruments. Typically, the conventional electrohydraulic nozzle flapper actuator system includes a nozzle coupled to a pressurized fluid supply and a flapper. As fluid is discharged from the nozzle, it displaces the flapper and the distance between the flapper and the nozzle is proportional to the force exerted by the fluid. An electric torque motor is commonly used to adjust the distance between the flapper and the nozzle by moving the flapper, thereby adjusting the pressure of the fluid.
There are several disadvantages associated with conventional nozzle flapper actuator systems. The electric torque motors utilized in conventional nozzle flapper actuator systems require external electrical power which is often an inconvenience to supply. There is also a tendency for dirt to accumulate between the nozzle and the flapper, thus making the system relatively sensitive to dirt. Moreover, conventional nozzle flapper actuator systems tend to be bulky.
Accordingly, there is a need for small nozzle flapper actuator system which is relatively insensitive to dirt and which requires no external source of electrical power.